There is a semiconductor device having a stacked body in which a plurality of conductive layers and a plurality of insulating layers are alternately stacked.
As a semiconductor device having such a stacked body, for example, there is a three-dimensional stacked memory.
In a method of manufacturing a three-dimensional stacked memory, it is required to form a through hole that passes through a stacked body in a stacked direction. However, it is difficult to form a through hole by etching because a plurality of conductive layers and a plurality of insulating layers are alternately stacked. Therefore, a substitution process that forms an insulating layer in a portion where sacrificial layers are removed through a through hole after alternately stacking a plurality of conductive layers and a plurality of sacrificial layers, forming a through hole that passes through the stacked body in the stacked direction, and removing the sacrificial layer through the through hole is used.
Here, a lithographic mark such as an alignment mark or an inspection mark (an alignment measurement mark) is provided in the stacked body. Further, a mark for inspecting a photo mask may be transferred onto the stacked body.
In this case, if the sacrificial layers are removed by the substitution process, the conductive layers are not supported in a portion where such a mark is provided but the stacked conductive layers may be undesirably partially collapsed.